Self-adjusting brake-shoe.



A. L. GOODKNIGHT.

SELF ADJUSTING BRAKE SHOE.

APPLICATION IILIBD MAR. a, 1913.

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Patented Sept. 9, 1913.

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ALVA I1. GOODKNIGHT, 0F HEAVENER, OKLAHOMA.

SELF-ADJUSTING BRAKE-SHOE.

Specification of Letters Patent.

Application filed March 8, 1913. Serial No. 752,921.

To all whom, it may concern:

Be it known that I, ALVA L. GOODKNIGHT, a citizen of the United States, residing at Heavener, in the county of Le Flore and State of Oklahoma, have invented a new and useful Improvement in Self-Adjusting Brake-Shoes, of which the following is a specification.

My invention relates to improvements in self-adjusting brake-shoes for car-wheel brakes by which the shoe is automatically adjusted to the car-wheel when the bearing surface of the shoe is wasted by frictional engagement with the wheel-tread during the application of the brake to retard the momentum of the car or train of cars.

The objects of my invention are: First: to provide a simple, cheap, durable and efficient brake-shoe provided with means for automatically adjusting the shoe to the wheel-tread of the car-wheel whenever the bearing portion becomes wasted. Second: to provide a brake-shoe which may be adjusted to the wheel-tread without involving the brake-head in such movement. Third: to provide a self-adjusting brake-shoe which may be adjusted to the wheel-tread regardless of waste of the shoe or variable slack in the brake-rigging. I attain these objects by. the mechanism illustrated in the accompanying drawings, in which,

Figure 1. is a rear elevation of a brakehead provided with my invention, and partly sectioned on the line I, I in Fig. 2. Fig. 2. a sectional view of my invention applied to a brake-head, on the line II, II, in Fig. 1. Fig. 3. a sectional view of my invention on line III, III, in Fig. 2, and Fig. 4. a sectional View on the line IV, IV in Fig. 2. Fig. 5. is a plan view of the brush and section of brake-shoe.

Similar numerals refer to similar parts throughout the drawing.

The numeral 1 indicates a section of a car-wheel, the tread of which is engaged by a brake-shoe 2, carried by a brake-head 3 having a neck 4 provided with flanges 5, 5 secured to a brake-beam 6 by the fastening device 7. The brake-shoe 2 is provided with upwardly-extending side flanges 8 and 9 adapted for guiding the forward movement of the shoe to efi'ect its proper adjustment to the wheel-tread, and also to provide strength and rigidity to the shoe. The said flanges are gently rounded at their upper terminal ends. A rib 10 is formed transversely the inside-surface of each of said flanges 8 and 9 adjacent their terminal ends, and a similar rib is similarly formed intermediate the length of said flanges. Said ribs 10 are each inclined upwardly and each provided with a plurality of ratchet teeth 11 upon the under-side adapted for a purpose hereinafter described.

A metal brush 12 comprising a plurality of -metal leaves 13 arranged in parallel lines and bearing upon each other are cast integral with the lower extremity of the brake-shoe 2 by their inner ends, their opposite ends being free, the said brush 12 being positioned to lie substantially at right angles to the ribs 10 adjacent the lower ends of the flanges 8 and 9 thus bringing the bottom leaf of the brush in contact with the wheel-tread. The metal brush 12 is specially designed and located to provide automatic-selective adjustment of the brakeshoe to the wheel-tread whenever the bear ing surface of the shoe is wasted by the wear and tear incident to the braking-process, and also for the purpose of sustaining the brake-shoe in place upon'the brake-head.

The opposite sides of the brake-head 3 are each provided adjacent their terminal ends with a recess 14, and a similar recess is provided intermediate the length of the brakehead in both sides thereof. The sides of said recesses are each slanted or inclined similarly to the inclination of the ribs 10, and the lower side of each recess is provided with a plurality of notches 15, adapted to engage the ratchet-teeth 11 on the ribs 10, when the brake-shoe 2 and the brake-head 3 are operatively assembled, as hereinafter described, and as shown in Fig. 2.

The downwardly-extending lugs 16 and 17 integral with the lower extremity of the brake-head 3 are apertured transversely, in which apertures a heel-bolt 18 provided with a key 19 is secured for the purpose of supporting the brush 12 and the brake-shoe 2 in proper position on the brake-head.

Patented Sept. 9, 1913.

A tension spring 20 connected at one end with the upper end of the brake-shoe and its opposite end connected with a T-shaped arm 21 rigid with the brake-head 3 provides means for maintaining proper adjustment of the ratchet-teeth on the ribs 10 with the notches 15 in the seat of the recesses 1a in the brake-head 3.

The upwardly-extending T-shaped arm 21, rigid with the brake-head 3, is provided at the angles formed by the cross-piece with movably pivoted rollers 22, 22, and a similar movably pivoted roller 23 is provided intermediate the cross-piece and in vertical line with the T-shaped arm 21. A roller 24 is movably mounted on one end of the crosspiece and a similar roller 25 is similarly mounted on its opposite end.

A bracket 26 suspended by and attached to the arch-bar 27 of the car-truck is provided with a movably-secured gate 28 and a longitudinally-extending slot 29 having its upper edges beveled inwardly and downwardly provides means for suspending the operatively assembled brake to obtain the automatic adjustment of the brake-shoe to the car-wheel. The rollers 22 normally rest on the beveled-surface of the upper-edges of the slot 29. If disturbed by lateral movements of the brake the rollers rotate up said beveled-surface and return to normal position when the disturbance ceases. The roller 23 remains normally idle until thrust upwardly by vertical movement of the brake, to impinge upon the upper wall of the bracket, in which position it performs functions substantially similar to the roller 22, rotating forwardly and backwardly responsive to lateral movements of the brake when in this position, and returns to its idle position when the rollers 22 are in their normal position. The rollers 24: and 25 are adapted to rotate up and down the inclined floor of the bracket responsive to the forward and backward alternate movements of the brake. When the brake is applied the rollers are advanced up the incline, as shown in Fig. 2 and when the brake is released the rollers return down the incline to adjacent the gate 28.

To suspend the T-shaped arm 21 in the bracket 26 the gate 28 at the bottom of the inclined floor is opened and the cross-piece entered bringing the vertical portion of said arm into the slot 29. The gate is closed and fastened. To remove the said arm the gate 28 is opened and the arm drops by gravity from the inclined floor of the bracket 26 through the gateway.

A brake-key slot 30 is vertically apertured in the brake-head to provide for interchange of the old and new types of brake-shoes.

Assuming that the brake apparatus is operatively assembled as hereinabove described,

the brake-shoe 2 is pressed against the carwheel and withdrawn therefrom by means of force applied to the brake-beam to which the brake is secured. hen the ordinary brake-shoe is reduced by waste incident to the service conditions the stroke of the piston, if one is used, is thereby lengthened, and if the wear is considerable the piston ultimately will impinge upon the non-pressure head thus decreasing the efiiciency of the air-brake by a loss of braking-power. The brake-shoe 2 wastes until the lower leaf of the brush 12 is also wasted. Immediately this happens the brake-shoe drops by gravity bringing the next leaf of the brush 12 in position to bear against the car-wheel, and the notched teeth in the ribs 10 drop one notch, in which position the shoe remains until the second leaf of the brush is entirely wasted, When the shoe again drops by gravity as before stated, and continuing thus step by step until the shoe is so reduced and a new shoe applied. The ratchetteeth engaged by the notched recess prevent absolutely any retrograde movement of the brake-shoe in the brake-head, and the inclination of the ribs 10 upon the flanges 8 and 9 having the ratchet teeth 11 provides accurate adjustment of the brake-shoe to the carwheel, and maintains its bearingsurface a non-variable distance from the brake-beam, as illustrated by the lines II and line 31, thereby obtaining a uniform piston stroke, if air is used, and an even application of the brakes, regardless whether air pressure or manual brakes are used. WVhen the lower leaf of the brush 12 is wasted, if the brake assumes release position, the cross-piece carried by the T-shaped arm, drops a distance down the inclined floor of the bracket, the movement operating to withdraw the brake shoe apart from the wheel, permitting the brake-shoe to drop to bring the neXt leaf of the brush to engage the bolt 18.

To operatively assemble the improved brake-shoe with the brake-head, the ribs 10 are respectively entered in the recesses 14L in the brake-head 3 with the upper surface of each rib impinging upon the upper edge of the recesses 14 to prevent the ratchet teeth 11 on the ribs 10 engaging the notches 15 in the recesses 14 and until the said ribs are completely entered, bringing the body of the brake-shoe against the brake-head. The brake-shoe is then permitted to drop and the brush 12 carried by the brake-shoe is entered between the lugs 16 and 17 on the brake-head 3, and the bolt 18 inserted through said lugs beneath said brush 12 and secured therein by the key 19. The brakeshoe is thus held in position upon the brakehead. To remove the brake-shoe from engagement with the brake-head the spring 20 is disengaged and the key 19 is withdrawn from the bolt 18 and the said bolt removed from the lugs 16 and 17, when the brakeshoe will drop from engagement with the brake-head.

I preferably make my self-adjusting brakeshoe and the rigging of iron and steel.

Having fully described my invention I claim:

1. A self-adjusting brake-shoe, comprising a brake-head having a plurality of notched recesses in its opposing sides, a brake-shoe proper having a plurality of ribs provided with ratchet-teeth in engagement with the notches in said brake-head, and having a metal-brush integral with its lower terminal extreme adapted to wastingly engage the car'wheel to provide re-adjustment of the said brake-shoe, and means for yield ingly suspending the brake-head from the cartruck.

2. The combination with a car-truck, of an inclined bracket suspended from said cartruck, a brake-head provided with a plurality of notched recesses in its opposing sides and having an upwardly-extending T- shaped arm carrying a cross-head provided with rollers movably mounted in said bracket, a brake-shoe proper having upwardly-extending side flanges provided with a plurality of ribs having ratchet-teeth in engagement with the notched recesses in said brake-head, a tension-spring connecting said brake-shoe and said brake-head, and a brush having a plurality of leaves in parallelism wastingly engaged by the car-wheel and formed integral with the brakeshoe adapted for adjusting the brake-shoe in the brakehead.

3. In a self-adjusting brake-shoe, a shoe proper provided with upwardly-extcnding opposing side flanges in engagement with the brake-head having a plurality of ribs integral with the inside-surfaces of said flanges and provided with ratchet-teeth slidingly engaged by notches provided in a plurality of recesses in the sides of said brakehead, and means for yieldingly suspending the brake-head from the car-truck, and means for locking the brake-shoe in the brake-head.

4:. The combination with car-truck, of an inclined bracket suspended from said car-truck, a brake-head provided with a plurality of notched recesses in its opposing sides and having an upwardly-extending T- shaped arm carrying a cross-head provided with rollers movably mounted in said bracket, a brake-shoe proper having upwardly-extending side flanges provided with a plurality of ribs having ratchet-teeth in engagement with the notched recesses in said brake-head, a tension-spring connecting said brake-shoe and said brake-head, and a brush having a plurality of leaves in parallelism wastingly engaged by the car-wheel and formed integral with the brake-shoe adapted for self-adjustment of the brake-shoe in the brake-head.

5. In a self-adjusting brake-shoe, a brakehead provided with means adapted for the self-adjustment of the brake-shoe on said brake-head, said means comprising ratchet teeth rigid with the brakeshoe adapted to limit backward movement of the brake-shoe, and a metal brush integral with the brakeshoe having a plurality of leaves in parallelism wastingly engaged by the car-wheel.

6. In a self-adjusting brake-shoe, an inclined bracket suspended by the car-truck provided centrally with a longitudinal slot having its upper edges beveled adapted for the passage therethrough of an upwardly extending T-shaped arm integral with the brake-head, said arm having a cross-head provided with rollers adapted for lateral travel over said beveled edges of said slot, a gate removably secured to said bracket adapted for the ingress and egress of the cross-head on said T-shaped arm, and means for locking said gate.

7. In a self-adjusting brake-shoe, the combination with the brake-rigging, of a brakehead provided with notches, and a brakeshoe movably mounted on the brake-head and having ratchet teeth in engagement with the notches in the brake-head adapted to prevent backward movement of the brakeshoe.

8. In a self-adjusting brake-shoe, the combination with the brake-rigging, of a brakehead provided with notches, a brake-shoe movably mounted on the brake-head and having ratchet teeth in engagement with the notches on the brakehead adapted to prevent backward movement of the brake-shoe, and means for movably suspending the brake-head from the car.

9. In a self-adjusting brake-shoe, the combination with the car truck, of a bracket having a guiding slot, a brake-head having notches movably suspended by the bracket, and a brake-shoe movably mounted on the brake-head and having ratchet teeth in engagement with the notches on the brakehead adapted to hold the brake-shoe on the wheel-tread.

10. In a self-adjusting brake-shoe, the combination witha brake-head having a plurality of recesses in its opposing sides provided with notches, of a brake-shoe provided with upwardly-extending side flanges having a plurality of ribs provided with ratchet teeth supportingly engaged by the notches in the recesses in said brake-head, and means for movably suspending the brake-head from the car-truck.

11. In a self-adjusting brake-shoe, an inclined bracket suspended by the car truck provided centrally with a longitudinal slot and a gate removably secured to said bracket having its upper edges beveled adapted for adapted for the ingress and egress of the the passage therethrough of an upwardlycross-head on said T-shaped arm.

extending T-shaped arm integral with the ALVA L. GOODKNIGHT. brake-head, said arm having a cross-head \Vitnesses:

provided With rollers adapted for lateral ROBERT O. MOLIN,

travel over said beveled edges of said slot, ANNIE L. GREEK.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

